Demand for alternative fuels, such as bio-diesel, has increased the need for sources of ethanol. Over the past few years, a renewed interest to further develop processes to manufacture ethanol from raw starch fermentation of various biomass sources such as corn (maize) has emerged. Research and development in this arena has spawned investigation as to the ways to boost profits by focusing on the commercial value of oil-containing byproducts produced during fermentation (hereinafter referred to as “fermentation products”). As a result of these investigations, various processes have emerged that focus on recovering oil product from these valuable by fermentation products.
Various processes for recovering oil from a fermentation product are currently known in the art. Such processes, however, can be expensive, inefficient or even dangerous. For example, some process, such as that set forth in WO 2008/039859, utilize a solvent extraction technique that, in turn, requires the use of volatile organic compounds such as hexane. Other processes, such as that set forth in U.S. Application Publication No. 2007/0238891, utilize high amounts of heat. Still other conventional processes, such as that set forth in U.S. Application Publication No. 2006/0041152 and 2006/0041153, simply apply a centrifugal force to a fermented product in an attempt to separate an oil product.
Conventional processes for recovering oil from a fermentation product can sacrifice oil quality such that the oil contains a high level of free fatty acids. The presence of a high level of free fatty acids can hamper the production of end products such as, for example, the yield and quality of any bio-diesel eventually produced with the oil as a feedstock. Processes for producing ethanol, such as the process set forth in WO 2004/081193, produce fermentation byproducts which contain increased levels of oils while maintaining a low level of free fatty acids. However, upon application of a centrifugal force to the fermented product, an emulsion can form which effectively locks the valuable oil within the emulsion. Thus, a problem exists in that both conventional and novel processes, alike, cannot effectively, efficiently or safely separate or “break” quality oil from a fermented product.